rtmpproto.c

 * successful response, we will return set the value to number (otherwise number
 * will not be changed).
 *
 * @return 0 if reading the value succeeds, negative value otherwise
 */
static int read_number_result(RTMPPacket *pkt, double *number)
{
    // We only need to fit "_result" in this.
    uint8_t strbuffer[8];
    int stringlen;
    double numbuffer;
    GetByteContext gbc;

    bytestream2_init(&gbc, pkt->data, pkt->size);

    // Value 1/4: "_result" as AMF_STRING
    if (ff_amf_read_string(&gbc, strbuffer, sizeof(strbuffer), &stringlen))
        return AVERROR_INVALIDDATA;
    if (strcmp(strbuffer, "_result"))
        return AVERROR_INVALIDDATA;
    // Value 2/4: The callee reference number
    if (ff_amf_read_number(&gbc, &numbuffer))
        return AVERROR_INVALIDDATA;
    // Value 3/4: Null
    if (ff_amf_read_null(&gbc))
        return AVERROR_INVALIDDATA;
    // Value 4/4: The response as AMF_NUMBER
    if (ff_amf_read_number(&gbc, &numbuffer))
        return AVERROR_INVALIDDATA;
    else
        *number = numbuffer;

    return 0;
}

static int handle_invoke_result(URLContext *s, RTMPPacket *pkt)
{
    RTMPContext *rt = s->priv_data;
    char *tracked_method = NULL;
    int ret = 0;

    if ((ret = find_tracked_method(s, pkt, 10, &tracked_method)) < 0)
        return ret;

    if (!tracked_method) {
        /* Ignore this reply when the current method is not tracked. */
        return ret;
    }

    if (!strcmp(tracked_method, "connect")) {
        if (!rt->is_input) {
            if ((ret = gen_release_stream(s, rt)) < 0)
                goto fail;

            if ((ret = gen_fcpublish_stream(s, rt)) < 0)
                goto fail;
        } else {
            if ((ret = gen_server_bw(s, rt)) < 0)
                goto fail;
        }

        if ((ret = gen_create_stream(s, rt)) < 0)
            goto fail;

        if (rt->is_input) {
            /* Send the FCSubscribe command when the name of live
             * stream is defined by the user or if it's a live stream. */
            if (rt->subscribe) {
                if ((ret = gen_fcsubscribe_stream(s, rt, rt->subscribe)) < 0)
                    goto fail;
            } else if (rt->live == -1) {
                if ((ret = gen_fcsubscribe_stream(s, rt, rt->playpath)) < 0)
                    goto fail;
            }
        }
    } else if (!strcmp(tracked_method, "createStream")) {
        double stream_id;
        if (read_number_result(pkt, &stream_id)) {
            av_log(s, AV_LOG_WARNING, "Unexpected reply on connect()\n");
        } else {
            rt->stream_id = stream_id;
        }

        if (!rt->is_input) {
            if ((ret = gen_publish(s, rt)) < 0)
                goto fail;
        } else {
            if (rt->live != -1) {
                if ((ret = gen_get_stream_length(s, rt)) < 0)
                    goto fail;
            }
            if ((ret = gen_play(s, rt)) < 0)
                goto fail;
            if ((ret = gen_buffer_time(s, rt)) < 0)
                goto fail;
        }
    } else if (!strcmp(tracked_method, "getStreamLength")) {
        if (read_number_result(pkt, &rt->duration)) {
            av_log(s, AV_LOG_WARNING, "Unexpected reply on getStreamLength()\n");
        }
    }

fail:
    av_free(tracked_method);
    return ret;
}

static int handle_invoke_status(URLContext *s, RTMPPacket *pkt)
{
    RTMPContext *rt = s->priv_data;
    const uint8_t *data_end = pkt->data + pkt->size;
    const uint8_t *ptr = pkt->data + RTMP_HEADER;
    uint8_t tmpstr[256];
    int i, t;

    for (i = 0; i < 2; i++) {
        t = ff_amf_tag_size(ptr, data_end);
        if (t < 0)
            return 1;
        ptr += t;
    }

    t = ff_amf_get_field_value(ptr, data_end, "level", tmpstr, sizeof(tmpstr));
    if (!t && !strcmp(tmpstr, "error")) {
        t = ff_amf_get_field_value(ptr, data_end,
                                   "description", tmpstr, sizeof(tmpstr));
        if (t || !tmpstr[0])
            t = ff_amf_get_field_value(ptr, data_end, "code",
                                       tmpstr, sizeof(tmpstr));
        if (!t)
            av_log(s, AV_LOG_ERROR, "Server error: %s\n", tmpstr);
        return -1;
    }

    t = ff_amf_get_field_value(ptr, data_end, "code", tmpstr, sizeof(tmpstr));
    if (!t && !strcmp(tmpstr, "NetStream.Play.Start")) rt->state = STATE_PLAYING;
    if (!t && !strcmp(tmpstr, "NetStream.Play.Stop")) rt->state = STATE_STOPPED;
    if (!t && !strcmp(tmpstr, "NetStream.Play.UnpublishNotify")) rt->state = STATE_STOPPED;
    if (!t && !strcmp(tmpstr, "NetStream.Publish.Start")) rt->state = STATE_PUBLISHING;
    if (!t && !strcmp(tmpstr, "NetStream.Seek.Notify")) rt->state = STATE_PLAYING;

    return 0;
}

static int handle_invoke(URLContext *s, RTMPPacket *pkt)
{
    RTMPContext *rt = s->priv_data;
    int ret = 0;

    //TODO: check for the messages sent for wrong state?
    if (ff_amf_match_string(pkt->data, pkt->size, "_error")) {
        if ((ret = handle_invoke_error(s, pkt)) < 0)
            return ret;
    } else if (ff_amf_match_string(pkt->data, pkt->size, "_result")) {
        if ((ret = handle_invoke_result(s, pkt)) < 0)
            return ret;
    } else if (ff_amf_match_string(pkt->data, pkt->size, "onStatus")) {
        if ((ret = handle_invoke_status(s, pkt)) < 0)
            return ret;
    } else if (ff_amf_match_string(pkt->data, pkt->size, "onBWDone")) {
        if ((ret = gen_check_bw(s, rt)) < 0)
            return ret;
    } else if (ff_amf_match_string(pkt->data, pkt->size, "releaseStream") ||
               ff_amf_match_string(pkt->data, pkt->size, "FCPublish")     ||
               ff_amf_match_string(pkt->data, pkt->size, "publish")       ||
               ff_amf_match_string(pkt->data, pkt->size, "play")          ||
               ff_amf_match_string(pkt->data, pkt->size, "_checkbw")      ||
               ff_amf_match_string(pkt->data, pkt->size, "createStream")) {
        if ((ret = send_invoke_response(s, pkt)) < 0)
            return ret;
    }

    return ret;
}

static int update_offset(RTMPContext *rt, int size)
{
    int old_flv_size;

    // generate packet header and put data into buffer for FLV demuxer
    if (rt->flv_off < rt->flv_size) {
        // There is old unread data in the buffer, thus append at the end
        old_flv_size  = rt->flv_size;
        rt->flv_size += size;
    } else {
        // All data has been read, write the new data at the start of the buffer
        old_flv_size = 0;
        rt->flv_size = size;
        rt->flv_off  = 0;
    }

    return old_flv_size;
}

static int append_flv_data(RTMPContext *rt, RTMPPacket *pkt, int skip)
{
    int old_flv_size, ret;
    PutByteContext pbc;
    const uint8_t *data = pkt->data + skip;
    const int size      = pkt->size - skip;
    uint32_t ts         = pkt->timestamp;

    if (pkt->type == RTMP_PT_AUDIO) {
        rt->has_audio = 1;
    } else if (pkt->type == RTMP_PT_VIDEO) {
        rt->has_video = 1;
    }

    old_flv_size = update_offset(rt, size + 15);

    if ((ret = av_reallocp(&rt->flv_data, rt->flv_size)) < 0) {
        rt->flv_size = rt->flv_off = 0;
        return ret;
    }
    bytestream2_init_writer(&pbc, rt->flv_data, rt->flv_size);
    bytestream2_skip_p(&pbc, old_flv_size);
    bytestream2_put_byte(&pbc, pkt->type);
    bytestream2_put_be24(&pbc, size);
    bytestream2_put_be24(&pbc, ts);
    bytestream2_put_byte(&pbc, ts >> 24);
    bytestream2_put_be24(&pbc, 0);
    bytestream2_put_buffer(&pbc, data, size);
    bytestream2_put_be32(&pbc, size + RTMP_HEADER);

    return 0;
}

static int handle_notify(URLContext *s, RTMPPacket *pkt)
{
    RTMPContext *rt  = s->priv_data;
    uint8_t commandbuffer[64];
    char statusmsg[128];
    int stringlen, ret, skip = 0;
    GetByteContext gbc;

    bytestream2_init(&gbc, pkt->data, pkt->size);
    if (ff_amf_read_string(&gbc, commandbuffer, sizeof(commandbuffer),
                           &stringlen))
        return AVERROR_INVALIDDATA;

    if (!strcmp(commandbuffer, "onMetaData")) {
        // metadata properties should be stored in a mixed array
        if (bytestream2_get_byte(&gbc) == AMF_DATA_TYPE_MIXEDARRAY) {
            // We have found a metaData Array so flv can determine the streams
            // from this.
            rt->received_metadata = 1;
            // skip 32-bit max array index
            bytestream2_skip(&gbc, 4);
            while (bytestream2_get_bytes_left(&gbc) > 3) {
                if (ff_amf_get_string(&gbc, statusmsg, sizeof(statusmsg),
                                      &stringlen))
                    return AVERROR_INVALIDDATA;
                // We do not care about the content of the property (yet).
                stringlen = ff_amf_tag_size(gbc.buffer, gbc.buffer_end);
                if (stringlen < 0)
                    return AVERROR_INVALIDDATA;
                bytestream2_skip(&gbc, stringlen);

                // The presence of the following properties indicates that the
                // respective streams are present.
                if (!strcmp(statusmsg, "videocodecid")) {
                    rt->has_video = 1;
                }
                if (!strcmp(statusmsg, "audiocodecid")) {
                    rt->has_audio = 1;
                }
            }
            if (bytestream2_get_be24(&gbc) != AMF_END_OF_OBJECT)
                return AVERROR_INVALIDDATA;
        }
    }

    // Skip the @setDataFrame string and validate it is a notification
    if (!strcmp(commandbuffer, "@setDataFrame")) {
        skip = gbc.buffer - pkt->data;
        ret = ff_amf_read_string(&gbc, statusmsg,
                                 sizeof(statusmsg), &stringlen);
        if (ret < 0)
            return AVERROR_INVALIDDATA;
    }

    return append_flv_data(rt, pkt, skip);
}

/**
 * Parse received packet and possibly perform some action depending on
 * the packet contents.
 * @return 0 for no errors, negative values for serious errors which prevent
 *         further communications, positive values for uncritical errors
 */
static int rtmp_parse_result(URLContext *s, RTMPContext *rt, RTMPPacket *pkt)
{
    int ret;

#ifdef DEBUG
    ff_rtmp_packet_dump(s, pkt);
#endif

    switch (pkt->type) {
    case RTMP_PT_BYTES_READ:
        av_log(s, AV_LOG_TRACE, "received bytes read report\n");
        break;
    case RTMP_PT_CHUNK_SIZE:
        if ((ret = handle_chunk_size(s, pkt)) < 0)
            return ret;
        break;
    case RTMP_PT_PING:
        if ((ret = handle_ping(s, pkt)) < 0)
            return ret;
        break;
    case RTMP_PT_CLIENT_BW:
        if ((ret = handle_client_bw(s, pkt)) < 0)
            return ret;
        break;
    case RTMP_PT_SERVER_BW:
        if ((ret = handle_server_bw(s, pkt)) < 0)
            return ret;
        break;
    case RTMP_PT_INVOKE:
        if ((ret = handle_invoke(s, pkt)) < 0)
            return ret;
        break;
    case RTMP_PT_VIDEO:
    case RTMP_PT_AUDIO:
    case RTMP_PT_METADATA:
    case RTMP_PT_NOTIFY:
        /* Audio, Video and Metadata packets are parsed in get_packet() */
        break;
    default:
        av_log(s, AV_LOG_VERBOSE, "Unknown packet type received 0x%02X\n", pkt->type);
        break;
    }
    return 0;
}

static int handle_metadata(RTMPContext *rt, RTMPPacket *pkt)
{
    int ret, old_flv_size, type;
    const uint8_t *next;
    uint8_t *p;
    uint32_t size;
    uint32_t ts, cts, pts = 0;

    old_flv_size = update_offset(rt, pkt->size);

    if ((ret = av_reallocp(&rt->flv_data, rt->flv_size)) < 0) {
        rt->flv_size = rt->flv_off = 0;
        return ret;
    }

    next = pkt->data;
    p    = rt->flv_data + old_flv_size;

    /* copy data while rewriting timestamps */
    ts = pkt->timestamp;

    while (next - pkt->data < pkt->size - RTMP_HEADER) {
        type = bytestream_get_byte(&next);
        size = bytestream_get_be24(&next);
        cts  = bytestream_get_be24(&next);
        cts |= bytestream_get_byte(&next) << 24;
        if (!pts)
            pts = cts;
        ts += cts - pts;
        pts = cts;
        if (size + 3 + 4 > pkt->data + pkt->size - next)
            break;
        bytestream_put_byte(&p, type);
        bytestream_put_be24(&p, size);
        bytestream_put_be24(&p, ts);
        bytestream_put_byte(&p, ts >> 24);
        memcpy(p, next, size + 3 + 4);
        p    += size + 3;
        bytestream_put_be32(&p, size + RTMP_HEADER);
        next += size + 3 + 4;
    }
    if (p != rt->flv_data + rt->flv_size) {
        av_log(NULL, AV_LOG_WARNING, "Incomplete flv packets in "
                                     "RTMP_PT_METADATA packet\n");
        rt->flv_size = p - rt->flv_data;
    }

    return 0;
}

/**
 * Interact with the server by receiving and sending RTMP packets until
 * there is some significant data (media data or expected status notification).
 *
 * @param s          reading context
 * @param for_header non-zero value tells function to work until it
 * gets notification from the server that playing has been started,
 * otherwise function will work until some media data is received (or
 * an error happens)
 * @return 0 for successful operation, negative value in case of error
 */
static int get_packet(URLContext *s, int for_header)
{
    RTMPContext *rt = s->priv_data;
    int ret;

    if (rt->state == STATE_STOPPED)
        return AVERROR_EOF;

    for (;;) {
        RTMPPacket rpkt = { 0 };
        if ((ret = ff_rtmp_packet_read(rt->stream, &rpkt,
                                       rt->in_chunk_size, &rt->prev_pkt[0],
                                       &rt->nb_prev_pkt[0])) <= 0) {
            if (ret == 0) {
                return AVERROR(EAGAIN);
            } else {
                return AVERROR(EIO);
            }
        }

        // Track timestamp for later use
        rt->last_timestamp = rpkt.timestamp;

        rt->bytes_read += ret;
        if (rt->bytes_read > rt->last_bytes_read + rt->client_report_size) {
            av_log(s, AV_LOG_DEBUG, "Sending bytes read report\n");
            if ((ret = gen_bytes_read(s, rt, rpkt.timestamp + 1)) < 0)
                return ret;
            rt->last_bytes_read = rt->bytes_read;
        }

        ret = rtmp_parse_result(s, rt, &rpkt);

        // At this point we must check if we are in the seek state and continue
        // with the next packet. handle_invoke will get us out of this state
        // when the right message is encountered
        if (rt->state == STATE_SEEKING) {
            ff_rtmp_packet_destroy(&rpkt);
            // We continue, let the natural flow of things happen:
            // AVERROR(EAGAIN) or handle_invoke gets us out of here
            continue;
        }

        if (ret < 0) {//serious error in current packet
            ff_rtmp_packet_destroy(&rpkt);
            return ret;
        }
        if (rt->do_reconnect && for_header) {
            ff_rtmp_packet_destroy(&rpkt);
            return 0;
        }
        if (rt->state == STATE_STOPPED) {
            ff_rtmp_packet_destroy(&rpkt);
            return AVERROR_EOF;
        }
        if (for_header && (rt->state == STATE_PLAYING    ||
                           rt->state == STATE_PUBLISHING ||
                           rt->state == STATE_SENDING    ||
                           rt->state == STATE_RECEIVING)) {
            ff_rtmp_packet_destroy(&rpkt);
            return 0;
        }
        if (!rpkt.size || !rt->is_input) {
            ff_rtmp_packet_destroy(&rpkt);
            continue;
        }
        if (rpkt.type == RTMP_PT_VIDEO || rpkt.type == RTMP_PT_AUDIO) {
            ret = append_flv_data(rt, &rpkt, 0);
            ff_rtmp_packet_destroy(&rpkt);
            return ret;
        } else if (rpkt.type == RTMP_PT_NOTIFY) {
            ret = handle_notify(s, &rpkt);
            ff_rtmp_packet_destroy(&rpkt);
            return ret;
        } else if (rpkt.type == RTMP_PT_METADATA) {
            ret = handle_metadata(rt, &rpkt);
            ff_rtmp_packet_destroy(&rpkt);
            return 0;
        }
        ff_rtmp_packet_destroy(&rpkt);
    }
}

static int rtmp_close(URLContext *h)
{
    RTMPContext *rt = h->priv_data;
    int ret = 0, i, j;

    if (!rt->is_input) {
        rt->flv_data = NULL;
        if (rt->out_pkt.size)
            ff_rtmp_packet_destroy(&rt->out_pkt);
        if (rt->state > STATE_FCPUBLISH)
            ret = gen_fcunpublish_stream(h, rt);
    }
    if (rt->state > STATE_HANDSHAKED)
        ret = gen_delete_stream(h, rt);
    for (i = 0; i < 2; i++) {
        for (j = 0; j < rt->nb_prev_pkt[i]; j++)
            ff_rtmp_packet_destroy(&rt->prev_pkt[i][j]);
        av_freep(&rt->prev_pkt[i]);
    }

    free_tracked_methods(rt);
    av_freep(&rt->flv_data);
    ffurl_close(rt->stream);
    return ret;
}

/**
 * Insert a fake onMetadata packet into the FLV stream to notify the FLV
 * demuxer about the duration of the stream.
 *
 * This should only be done if there was no real onMetadata packet sent by the
 * server at the start of the stream and if we were able to retrieve a valid
 * duration via a getStreamLength call.
 *
 * @return 0 for successful operation, negative value in case of error
 */
static int inject_fake_duration_metadata(RTMPContext *rt)
{
    // We need to insert the metadata packet directly after the FLV
    // header, i.e. we need to move all other already read data by the
    // size of our fake metadata packet.

    uint8_t* p;
    // Keep old flv_data pointer
    uint8_t* old_flv_data = rt->flv_data;
    // Allocate a new flv_data pointer with enough space for the additional package
    if (!(rt->flv_data = av_malloc(rt->flv_size + 55))) {
        rt->flv_data = old_flv_data;
        return AVERROR(ENOMEM);
    }

    // Copy FLV header
    memcpy(rt->flv_data, old_flv_data, 13);
    // Copy remaining packets
    memcpy(rt->flv_data + 13 + 55, old_flv_data + 13, rt->flv_size - 13);
    // Increase the size by the injected packet
    rt->flv_size += 55;
    // Delete the old FLV data
    av_free(old_flv_data);

    p = rt->flv_data + 13;
    bytestream_put_byte(&p, FLV_TAG_TYPE_META);
    bytestream_put_be24(&p, 40); // size of data part (sum of all parts below)
    bytestream_put_be24(&p, 0);  // timestamp
    bytestream_put_be32(&p, 0);  // reserved

    // first event name as a string
    bytestream_put_byte(&p, AMF_DATA_TYPE_STRING);
    // "onMetaData" as AMF string
    bytestream_put_be16(&p, 10);
    bytestream_put_buffer(&p, "onMetaData", 10);

    // mixed array (hash) with size and string/type/data tuples
    bytestream_put_byte(&p, AMF_DATA_TYPE_MIXEDARRAY);
    bytestream_put_be32(&p, 1); // metadata_count

    // "duration" as AMF string
    bytestream_put_be16(&p, 8);
    bytestream_put_buffer(&p, "duration", 8);
    bytestream_put_byte(&p, AMF_DATA_TYPE_NUMBER);
    bytestream_put_be64(&p, av_double2int(rt->duration));

    // Finalise object
    bytestream_put_be16(&p, 0); // Empty string
    bytestream_put_byte(&p, AMF_END_OF_OBJECT);
    bytestream_put_be32(&p, 40 + RTMP_HEADER); // size of data part (sum of all parts above)

    return 0;
}

/**
 * Open RTMP connection and verify that the stream can be played.
 *
 * URL syntax: rtmp://server[:port][/app][/playpath]
 *             where 'app' is first one or two directories in the path
 *             (e.g. /ondemand/, /flash/live/, etc.)
 *             and 'playpath' is a file name (the rest of the path,
 *             may be prefixed with "mp4:")
 */
static int rtmp_open(URLContext *s, const char *uri, int flags)
{
    RTMPContext *rt = s->priv_data;
    char proto[8], hostname[256], path[1024], auth[100], *fname;
    char *old_app, *qmark, fname_buffer[1024];
    uint8_t buf[2048];
    int port;
    AVDictionary *opts = NULL;
    int ret;

    if (rt->listen_timeout > 0)
        rt->listen = 1;

    rt->is_input = !(flags & AVIO_FLAG_WRITE);

    av_url_split(proto, sizeof(proto), auth, sizeof(auth),
                 hostname, sizeof(hostname), &port,
                 path, sizeof(path), s->filename);

    if (strchr(path, ' ')) {
        av_log(s, AV_LOG_WARNING,
               "Detected librtmp style URL parameters, these aren't supported "
               "by the libavformat internal RTMP handler currently enabled. "
               "See the documentation for the correct way to pass parameters.\n");
    }

    if (auth[0]) {
        char *ptr = strchr(auth, ':');
        if (ptr) {
            *ptr = '\0';
            av_strlcpy(rt->username, auth, sizeof(rt->username));
            av_strlcpy(rt->password, ptr + 1, sizeof(rt->password));
        }
    }

    if (rt->listen && strcmp(proto, "rtmp")) {
        av_log(s, AV_LOG_ERROR, "rtmp_listen not available for %s\n",
               proto);
        return AVERROR(EINVAL);
    }
    if (!strcmp(proto, "rtmpt") || !strcmp(proto, "rtmpts")) {
        if (!strcmp(proto, "rtmpts"))
            av_dict_set(&opts, "ffrtmphttp_tls", "1", 1);

        /* open the http tunneling connection */
        ff_url_join(buf, sizeof(buf), "ffrtmphttp", NULL, hostname, port, NULL);
    } else if (!strcmp(proto, "rtmps")) {
        /* open the tls connection */
        if (port < 0)
            port = RTMPS_DEFAULT_PORT;
        ff_url_join(buf, sizeof(buf), "tls", NULL, hostname, port, NULL);
    } else if (!strcmp(proto, "rtmpe") || (!strcmp(proto, "rtmpte"))) {
        if (!strcmp(proto, "rtmpte"))
            av_dict_set(&opts, "ffrtmpcrypt_tunneling", "1", 1);

        /* open the encrypted connection */
        ff_url_join(buf, sizeof(buf), "ffrtmpcrypt", NULL, hostname, port, NULL);
        rt->encrypted = 1;
    } else {
        /* open the tcp connection */
        if (port < 0)
            port = RTMP_DEFAULT_PORT;
        if (rt->listen)
            ff_url_join(buf, sizeof(buf), "tcp", NULL, hostname, port,
                        "?listen&listen_timeout=%d",
                        rt->listen_timeout * 1000);
        else
            ff_url_join(buf, sizeof(buf), "tcp", NULL, hostname, port, NULL);
    }

reconnect:
    if ((ret = ffurl_open(&rt->stream, buf, AVIO_FLAG_READ_WRITE,
                          &s->interrupt_callback, &opts, s->protocols, s)) < 0) {
        av_log(s , AV_LOG_ERROR, "Cannot open connection %s\n", buf);
        goto fail;
    }

    if (rt->swfverify) {
        if ((ret = rtmp_calc_swfhash(s)) < 0)
            goto fail;
    }

    rt->state = STATE_START;
    if (!rt->listen && (ret = rtmp_handshake(s, rt)) < 0)
        goto fail;
    if (rt->listen && (ret = rtmp_server_handshake(s, rt)) < 0)
        goto fail;

    rt->out_chunk_size = 128;
    rt->in_chunk_size  = 128; // Probably overwritten later
    rt->state = STATE_HANDSHAKED;

    // Keep the application name when it has been defined by the user.
    old_app = rt->app;

    rt->app = av_malloc(APP_MAX_LENGTH);
    if (!rt->app) {
        ret = AVERROR(ENOMEM);
        goto fail;
    }

    //extract "app" part from path
    qmark = strchr(path, '?');
    if (qmark && strstr(qmark, "slist=")) {
        char* amp;
        // After slist we have the playpath, the full path is used as app
        av_strlcpy(rt->app, path + 1, APP_MAX_LENGTH);
        fname = strstr(path, "slist=") + 6;
        // Strip any further query parameters from fname
        amp = strchr(fname, '&');
        if (amp) {
            av_strlcpy(fname_buffer, fname, FFMIN(amp - fname + 1,
                                                  sizeof(fname_buffer)));
            fname = fname_buffer;
        }
    } else if (!strncmp(path, "/ondemand/", 10)) {
        fname = path + 10;
        memcpy(rt->app, "ondemand", 9);
    } else {
        char *next = *path ? path + 1 : path;
        char *p = strchr(next, '/');
        if (!p) {
            fname = next;
            rt->app[0] = '\0';
        } else {
            // make sure we do not mismatch a playpath for an application instance
            char *c = strchr(p + 1, ':');
            fname = strchr(p + 1, '/');
            if (!fname || (c && c < fname)) {
                fname = p + 1;
                av_strlcpy(rt->app, path + 1, FFMIN(p - path, APP_MAX_LENGTH));
            } else {
                fname++;
                av_strlcpy(rt->app, path + 1, FFMIN(fname - path - 1, APP_MAX_LENGTH));
            }
        }
    }

    if (old_app) {
        // The name of application has been defined by the user, override it.
        av_free(rt->app);
        rt->app = old_app;
    }

    if (!rt->playpath) {
        int len = strlen(fname);

        rt->playpath = av_malloc(PLAYPATH_MAX_LENGTH);
        if (!rt->playpath) {
            ret = AVERROR(ENOMEM);
            goto fail;
        }

        if (!strchr(fname, ':') && len >= 4 &&
            (!strcmp(fname + len - 4, ".f4v") ||
             !strcmp(fname + len - 4, ".mp4"))) {
            memcpy(rt->playpath, "mp4:", 5);
        } else {
            if (len >= 4 && !strcmp(fname + len - 4, ".flv"))
                fname[len - 4] = '\0';
            rt->playpath[0] = 0;
        }
        av_strlcat(rt->playpath, fname, PLAYPATH_MAX_LENGTH);
    }

    if (!rt->tcurl) {
        rt->tcurl = av_malloc(TCURL_MAX_LENGTH);
        if (!rt->tcurl) {
            ret = AVERROR(ENOMEM);
            goto fail;
        }
        ff_url_join(rt->tcurl, TCURL_MAX_LENGTH, proto, NULL, hostname,
                    port, "/%s", rt->app);
    }

    if (!rt->flashver) {
        rt->flashver = av_malloc(FLASHVER_MAX_LENGTH);
        if (!rt->flashver) {
            ret = AVERROR(ENOMEM);
            goto fail;
        }
        if (rt->is_input) {
            snprintf(rt->flashver, FLASHVER_MAX_LENGTH, "%s %d,%d,%d,%d",
                    RTMP_CLIENT_PLATFORM, RTMP_CLIENT_VER1, RTMP_CLIENT_VER2,
                    RTMP_CLIENT_VER3, RTMP_CLIENT_VER4);
        } else {
            snprintf(rt->flashver, FLASHVER_MAX_LENGTH,
                    "FMLE/3.0 (compatible; %s)", LIBAVFORMAT_IDENT);
        }
    }

    rt->client_report_size = 1048576;
    rt->bytes_read = 0;
    rt->has_audio = 0;
    rt->has_video = 0;
    rt->received_metadata = 0;
    rt->last_bytes_read = 0;
    rt->server_bw = 2500000;
    rt->duration = 0;

    av_log(s, AV_LOG_DEBUG, "Proto = %s, path = %s, app = %s, fname = %s\n",
           proto, path, rt->app, rt->playpath);
    if (!rt->listen) {
        if ((ret = gen_connect(s, rt)) < 0)
            goto fail;
    } else {
        if ((ret = read_connect(s, s->priv_data)) < 0)
            goto fail;
    }

    do {
        ret = get_packet(s, 1);
    } while (ret == AVERROR(EAGAIN));
    if (ret < 0)
        goto fail;

    if (rt->do_reconnect) {
        int i;
        ffurl_close(rt->stream);
        rt->stream       = NULL;
        rt->do_reconnect = 0;
        rt->nb_invokes   = 0;
        for (i = 0; i < 2; i++)
            memset(rt->prev_pkt[i], 0,
                   sizeof(**rt->prev_pkt) * rt->nb_prev_pkt[i]);
        free_tracked_methods(rt);
        goto reconnect;
    }

    if (rt->is_input) {
        // generate FLV header for demuxer
        rt->flv_size = 13;
        if ((ret = av_reallocp(&rt->flv_data, rt->flv_size)) < 0)
            goto fail;
        rt->flv_off  = 0;
        memcpy(rt->flv_data, "FLV\1\0\0\0\0\011\0\0\0\0", rt->flv_size);

        // Read packets until we reach the first A/V packet or read metadata.
        // If there was a metadata package in front of the A/V packets, we can
        // build the FLV header from this. If we do not receive any metadata,
        // the FLV decoder will allocate the needed streams when their first
        // audio or video packet arrives.
        while (!rt->has_audio && !rt->has_video && !rt->received_metadata) {
            if ((ret = get_packet(s, 0)) < 0)
               goto fail;
        }

        // Either after we have read the metadata or (if there is none) the
        // first packet of an A/V stream, we have a better knowledge about the
        // streams, so set the FLV header accordingly.
        if (rt->has_audio) {
            rt->flv_data[4] |= FLV_HEADER_FLAG_HASAUDIO;
        }
        if (rt->has_video) {
            rt->flv_data[4] |= FLV_HEADER_FLAG_HASVIDEO;
        }

        // If we received the first packet of an A/V stream and no metadata but
        // the server returned a valid duration, create a fake metadata packet
        // to inform the FLV decoder about the duration.
        if (!rt->received_metadata && rt->duration > 0) {
            if ((ret = inject_fake_duration_metadata(rt)) < 0)
                goto fail;
        }
    } else {
        rt->flv_size = 0;
        rt->flv_data = NULL;
        rt->flv_off  = 0;
        rt->skip_bytes = 13;
    }

    s->max_packet_size = rt->stream->max_packet_size;
    s->is_streamed     = 1;
    return 0;

fail:
    av_dict_free(&opts);
    rtmp_close(s);
    return ret;
}

static int rtmp_read(URLContext *s, uint8_t *buf, int size)
{
    RTMPContext *rt = s->priv_data;
    int orig_size = size;
    int ret;

    while (size > 0) {
        int data_left = rt->flv_size - rt->flv_off;

        if (data_left >= size) {
            memcpy(buf, rt->flv_data + rt->flv_off, size);
            rt->flv_off += size;
            return orig_size;
        }
        if (data_left > 0) {
            memcpy(buf, rt->flv_data + rt->flv_off, data_left);
            buf  += data_left;
            size -= data_left;
            rt->flv_off = rt->flv_size;
            return data_left;
        }
        if ((ret = get_packet(s, 0)) < 0)
           return ret;
    }
    return orig_size;
}

static int64_t rtmp_seek(URLContext *s, int stream_index, int64_t timestamp,
                         int flags)
{
    RTMPContext *rt = s->priv_data;
    int ret;
    av_log(s, AV_LOG_DEBUG,
           "Seek on stream index %d at timestamp %"PRId64" with flags %08x\n",
           stream_index, timestamp, flags);
    if ((ret = gen_seek(s, rt, timestamp)) < 0) {
        av_log(s, AV_LOG_ERROR,
               "Unable to send seek command on stream index %d at timestamp "
               "%"PRId64" with flags %08x\n",
               stream_index, timestamp, flags);
        return ret;
    }
    rt->flv_off = rt->flv_size;
    rt->state = STATE_SEEKING;
    return timestamp;
}

static int rtmp_pause(URLContext *s, int pause)
{
    RTMPContext *rt = s->priv_data;
    int ret;
    av_log(s, AV_LOG_DEBUG, "Pause at timestamp %d\n",
           rt->last_timestamp);
    if ((ret = gen_pause(s, rt, pause, rt->last_timestamp)) < 0) {
        av_log(s, AV_LOG_ERROR, "Unable to send pause command at timestamp %d\n",
               rt->last_timestamp);
        return ret;
    }
    return 0;
}

static int rtmp_write(URLContext *s, const uint8_t *buf, int size)
{
    RTMPContext *rt = s->priv_data;
    int size_temp = size;
    int pktsize, pkttype, copy;
    uint32_t ts;
    const uint8_t *buf_temp = buf;
    uint8_t c;
    int ret;

    do {
        if (rt->skip_bytes) {
            int skip = FFMIN(rt->skip_bytes, size_temp);
            buf_temp       += skip;
            size_temp      -= skip;
            rt->skip_bytes -= skip;
            continue;
        }

        if (rt->flv_header_bytes < RTMP_HEADER) {
            const uint8_t *header = rt->flv_header;
            int channel = RTMP_AUDIO_CHANNEL;
            copy = FFMIN(RTMP_HEADER - rt->flv_header_bytes, size_temp);
            bytestream_get_buffer(&buf_temp, rt->flv_header + rt->flv_header_bytes, copy);
            rt->flv_header_bytes += copy;
            size_temp            -= copy;
            if (rt->flv_header_bytes < RTMP_HEADER)
                break;

            pkttype = bytestream_get_byte(&header);
            pktsize = bytestream_get_be24(&header);
            ts = bytestream_get_be24(&header);
            ts |= bytestream_get_byte(&header) << 24;
            bytestream_get_be24(&header);
            rt->flv_size = pktsize;

            if (pkttype == RTMP_PT_VIDEO)
                channel = RTMP_VIDEO_CHANNEL;

            if (((pkttype == RTMP_PT_VIDEO || pkttype == RTMP_PT_AUDIO) && ts == 0) ||
                pkttype == RTMP_PT_NOTIFY) {
                if ((ret = ff_rtmp_check_alloc_array(&rt->prev_pkt[1],
                                                     &rt->nb_prev_pkt[1],
                                                     channel)) < 0)
                    return ret;
                // Force sending a full 12 bytes header by clearing the
                // channel id, to make it not match a potential earlier
                // packet in the same channel.
                rt->prev_pkt[1][channel].channel_id = 0;
            }

            //this can be a big packet, it's better to send it right here
            if ((ret = ff_rtmp_packet_create(&rt->out_pkt, channel,
                                             pkttype, ts, pktsize)) < 0)
                return ret;

            rt->out_pkt.extra = rt->stream_id;
            rt->flv_data = rt->out_pkt.data;
        }

        copy = FFMIN(rt->flv_size - rt->flv_off, size_temp);
        bytestream_get_buffer(&buf_temp, rt->flv_data + rt->flv_off, copy);
        rt->flv_off += copy;
        size_temp   -= copy;

        if (rt->flv_off == rt->flv_size) {
            rt->skip_bytes = 4;

            if (rt->out_pkt.type == RTMP_PT_NOTIFY) {
                // For onMetaData and |RtmpSampleAccess packets, we want
                // @setDataFrame prepended to the packet before it gets sent.
                // However, not all RTMP_PT_NOTIFY packets (e.g., onTextData
                // and onCuePoint).
                uint8_t commandbuffer[64];
                int stringlen = 0;
                GetByteContext gbc;

                bytestream2_init(&gbc, rt->flv_data, rt->flv_size);
                if (!ff_amf_read_string(&gbc, commandbuffer, sizeof(commandbuffer),
                                        &stringlen)) {